International Standard ISO-FIX has been established, specifying the method for fixing the child seat to the vehicle seat. Japanese Patent Application Laid-Open No. 2010-155516 (Patent Literature 1) discloses background art of the vehicle seat configured to store ISO-FIX compatible anchor capable of fixing the ISO-FIX type child seat. The vehicle seat disclosed in Patent Literature 1 has been made to accomplish the task of improving the child seat mountability without deteriorating seating feel when the child seat is demounted. The vehicle seat has an anchor member to be engaged with a fixture of the child seat, which is disposed at the back side of the seat main body constituted by the pad material and the skin material for covering the outer side of the pad material, a through path extending from the front surface to the anchor member, and the slit formed in the skin material at the front surface side of an insertion opening of the through path. The above-described vehicle seat includes an extension member provided for the slit, extending to the region outside the insertion opening.